Rhodioloside inhibits apoptosis of hippocampal neurons exposed to sevoflurane via cAMP/PKA signaling pathway

Purpose: Neural injury affects patients after using inhalational anesthetics such as sevoflurane. Rhodioloside, a compound which is obtained from the Rhodiola rosea plant has been implicated to be the most commonly used psychostimulant that can improve a range of conditions. The study was aimed at finding the molecular mechanism underlying the Rhodioloside treatment of sevoflurane-injured hippocampal neurons.Methods: Main hippocampal neurons, secluded from Sprague Dawley embryonic rats were employed to create an injury model using 3 % sevoflurane. The sevoflurane-injured hippocampal neurons were treated with varying concentrations (10, 20, 40 and 80 μM/ml) of Rhodioloside to create different experimental groups: RHSD10+SEV, RHSD20+SEV, RHSD40+SEV, RHSD80+SEV, while untreated cells were considered as the Control group. Cell viability was identified using the CCK-8 assay. The CFSE assay was used to verify the promotion function of Rhodioloside on cell differentiation of neurons. FCM assay was employed to determine cell proliferation and apoptosis. Expression levels of apoptosisrelated factors, like Caspase-3, Bcl-2 and Bax were examined by RT-qPCR, while Western blot was used to measure phosphorylation of PKA.Results: Rhodioloside stimulated cell viability and prevented cell apoptosis in sevoflurane-injured hippocampal neurons in doses between 10-80 μM. The apoptosis-inhibitory effect of Rhodioloside was observed to be through cAMP/PKA pathway activation. Also, expression levels of Bcl-2, and PKA were enhanced and the level of Caspase-3 and Bax was reduced in a dose-dependent pattern. The PKA inhibitor reversed the above observation in the 40 μM Rhodioloside-treatment.Conclusion: Rhodioloside promoted cell viability and prevented apoptosis of primary hippocampal neurons injured by sevoflurane, through cAMP/PKA pathway activation. Inhibition of PKA network deteriorated the function of Rhodioloside by stimulating cell apoptosis. Our findings present a novel evidence that Rhodioloside could attenuate neurotoxicity of inhalational anesthetics. Keywords: Cell apoptosis, cAMP/PKA pathway, Hippocampal neurons, Rhodioloside, Sevofluran

Risk Factors and Prevalence of Helicobacter pylori

Aim. The aim of this study was to investigate the prevalence and risk factors of H. pylori infection in areas with high prevalence of gastric cancer in Jiangsu Province, China. Methods. A prospective epidemiologic survey of H. pylori infection was accomplished in a natural population of 5417 individuals in Yangzhong city. Questionnaires and 13C-urea breath test for H. pylori infection were performed. Results. Among 5417 subjects who completed questionnaires and 13C-urea breath test, 3435 (63.41%) were H. pylori positive. The prevalence reached a peak at the age of 30–39 years (90.82%). There was significant difference between sexes and women had a higher infection rate than men. The prevalence of H. pylori infection was also associated with eating kipper food and fried food. No association between H. pylori prevalence and smoking or drinking was found. Compared to healthy individuals, people with dyspeptic diseases (peptic ulcer, gastroenteritis) presented a high prevalence of H. pylori infection. Using multivariate logistic regression analysis, age and history of peptic ulcer and gastroenteritis were the independent predictors for H. pylori infection. Conclusions. Yangzhong city had a high prevalence of H. pylori infection and was related to several risk factors. The underlying mechanisms are needed to be further investigated

Interference between two independent multi-temporal-mode thermal fields

We construct a general theoretical model for analyzing the intensity correlation of the field formed by mixing two independent multi-temporal-mode thermal fields. In the model, we use the intensity correlation function g(2) to characterize the mode property of the mixed thermal field. We find that g(2) of the mixed field is always less than that of the individual thermal field with less average mode number unless the two thermal fields are identical in mode property. The amount of drop in g(2) of the interference field depends on the relative overlap between the mode structures of two thermal fields and their relative strength. We successfully derive the analytical expressions of the upper bound and lower limit for g(2) of the interference field. Moreover, we verify the theoretical analysis by performing a series of experiments when the mode structures of two independent thermal fields are identical, orthogonal, and partially overlapped, respectively. The experimental results agree with theoretical predictions. Our investigation is useful for analyzing the signals carried by the intensity correlation of thermal fields

Optimised Power Error Comparison Strategy for Direct Power Control of the Open-winding Brushless Doubly-Fed Wind Power Generator

This paper presents the conceptual analysis and comparative simulation and experimental evaluation of a novel power error comparison direct power control (PEC-DPC) strategy of the open-winding brushless doubly-fed reluctance generator (OW-BDFRG) for wind energy conversion systems (WECSs). As one of the promising candidates for limited speed range application of pump-alike and wind turbine with partially-rated converter. The emerging OW-BDFRG employed for the proposed PEC-DPC is fed via dual low-cost two-level converters, while the DPC concept is derived from the fundamental dynamic analyses between the calculated and controllable electrical power and flux of the BDFRG with two stators measurable voltage and current. Compared to the traditional two-level and three-level converter systems, the OW-BDFRG requires lower rated capacity of power devices and switching frequency converter, though have more flexible switching mode, higher reliability, redundancy and fault tolerance capability. The performance correctness and effectiveness of the proposed DPC strategy with the selected and optimised switching vector scheme are evaluated and confirmed through computer simulation studies and experimental measurements on a 25 kW generator test rig

Influence of viral hepatitis status on prognosis in patients undergoing hepatic resection for hepatocellular carcinoma: a meta-analysis of observational studies

<p>Abstract</p> <p>Background</p> <p>The influence of viral hepatitis status on prognosis in patients undergoing hepatic resection for hepatocellular carcinoma (HCC) remains a matter of debate. This study is a meta-analysis of the available evidence.</p> <p>Methods</p> <p>A literature search was performed to identify comparative studies reporting postoperative survival of HCC in different types of viral hepatitis. Pooled odds ratios (OR) and weighted mean differences (WMD with 95% confidence intervals (95% CI) were calculated using either the fixed effects model or random effects model.</p> <p>Results</p> <p>Twenty studies matched the selection criteria and reported on 4744 subjects, of whom 2008 in the HBV-positive (B-HCC) group, 2222 in the HCV-positive (C-HCC) group, and 514 in the hepatitis B- and C-negative (NBNC-HCC). Meta-analysis showed that patients with HBV or HCV infection had a worse 5-year disease-free survival when compared to patients with NBNC-HCC (respectively: OR: 0.39, 95% CI: 0.28 to 0.53, P < 0.001; WMD: 0.37, 95% CI: 0.22 to 0.64, P < 0.001). There was a tendency toward higher 5-year overall survival rates in the NBNC-HCC group compared to those in the other two groups, although these differences were not statistically significant. Both the 5-year overall survival and disease-free survival were not different among the B-HCC and C-HCC groups.</p> <p>Conclusions</p> <p>Patients with positive serology for hepatitis B or C undergoing resection for HCC had a poor prognosis compared to patients with negative serology.</p

Controller Strategy for Open-Winding Brushless Doubly-Fed Wind Power Generator with Common Mode Voltage Elimination

This paper presents the theoretical derivation and implementation of a novel direct power control for open-winding brushless doubly-fed reluctance generator (OW-BDFRG). As one of the promising brushless candidates, the OW-BDFRG is characterized with two stator windings fed by a dual controllable two-level three-phase converters through a common DC bus with common mode voltage elimination. The parameter-free control strategy is designed to obtain maximum power point tracking with variable speed constant frequency (VSCF) for wind energy conversion systems (WECSs). Compared to the traditional three-level converter systems, the DC bus voltage, AC-side voltage and capacity ratings of the proposed converter system are notably high while the reliability, redundancy and fault tolerance are significantly improved. Effectiveness, correctness and robustness of the proposed control strategy and the common mode voltage elimination scheme are evaluated and confirmed through simulation and experimental tests on a 42 kW generator prototype typical for VSCF-WECS

Pt nanowire growth induced by Pt nanoparticles in application of the cathodes for Polymer Electrolyte Membrane Fuel Cells (PEMFCs)

Improving cathode performance at a lower Pt loading is critical in commercial PEMFC applications. A novel Pt nanowire (Pt-NW) cathode was developed by in-situ growth of Pt nanowires in carbon matrix consisting Pt nanoparticles (Pt-NPs). Characterization of TEM and XRD shows that the pre-existing Pt-NPs from Pt/C affect Pt-NW morphology and crystallinity and Pt profile crossing the matrix thickness. The cathode with Pt-NP loading of 0.005 mgPt-NP cm−2 and total cathode Pt loading of 0.205 mgPt cm−2 has the specific current density of 89.56 A gPt−1 at 0.9 V, which is about 110% higher than that of 42.58 A gPt−1 of the commercial gas diffusion layer (GDE) with Pt loading of 0.40 mg cm−2. When cell voltage is below 0.48 V, the Pt-NW cathode has better performance than the commercial GDE. It is believed that the excellent performance of the Pt-NW cathode is attributed to Pt-NP induction, therefore producing unique Pt-NW structure and efficient Pt utilization. A Pt-NW growth mechanism was proposed that Pt precursor diffuses into the matrix consisting of pre-existent Pt-NPs by concentration driving, and Pt-NPs provide priority sites for platinum depositing at early stage and facilitate Pt-NW growth